The present invention concerns a holder for a polished work used for holding the polished work when disk-shaped polished works including semiconductor wafers, aluminum disks or glass disks for hard disks, glass substrates for use in liquid crystal displays and disk-shaped ceramics are polished by a surface polishing apparatus, as well as a manufacturing method thereof.
For example, when disk-shaped polished work comprising, for example, a semiconductor wafer, aluminum disk or glass disk for hard disk, a glass substrate for use in a liquid crystal display and disk-shaped ceramics is polished by a surface polishing apparatus such as a lapping machine, a holder for polished work as shown in FIG. 11 is used for holding the polished work. The holder 30 for the polished work has several to several tens lapped material holding holes 32 for holding the lapped material 31 and has a gear 33 meshing with a sun gear and an internal gear of a surface polishing apparatus.
Known polished work holders can include, for example, metal holders comprising metal plates such as made of SK steels or stainless steels, holders having resin coating applied on the surface of the metal holders (referred to Japanese Published Unexamined Utility Model Application No. 4349/1983) and laminate holders formed by impregnating carbon fibers with resins (Japanese Published Unexamined Patent Application No. 143954/1983). Metal polished work holders comprising metal plate have working life ten times or more the polished work holder comprising resin plates developed subsequently in view of the polishing durability but have a drawback of sometimes damaging the polished work such as cracking or chipping by contact between the metal and the polished work in the work holding hole, which greatly deteriorates the yield of the polished product.
As a countermeasure for preventing such cracking or chipping of the polished work, a resin portion may be formed along the inner circumference of the work holding hole in which the work holding hole is manufactured by grinding a resin plate of a thickness identical with the metal plate, fitting the same to the inner circumference of the work holding hole and the surface of contact between the metal and the resin is secured by an adhesive. The polished work holder has an advantageous effect to some extent in that it can prevent occurrence of flaws such as cracking or chipping to the polished work but it lacks in the bonding reliability and the resin tends to drop easily from the adhesion portion. In addition, it requires a number of complicate manufacturing steps, is poor in the productivity and increases the cost, so that it has not yet been used generally.
Accordingly, this invention intends to provide a method of manufacturing a polished work holder and a polished work holder comprising a metal plate, having high productivity and of a reduced cost when a resin portion is formed to the inner circumference of a holding hole and in which the resin does not drop of the bonding portion without using the adhesive or the like.
In view of the foregoing situations, the present inventors have made an earnest study and, as a result, have accomplished the present invention based on the finding that a polished work holder can be manufactured at a high productivity and at a reduced cost in which resin or resin lamination molding product does not drop off the adhesion portion by providing a metal plate having through holes formed for holding the polished work, chamfering the periphery of the through holes partially or entirely and then injection molding a resin to the chamfered portion and the penetrated portion of the through holes, or providing a plurality of penetrating recesses to the inner surface of the through holes, chamfering protrusions defined by the penetrating recesses partially or entirely or forming unevenness on the lateral surface at the top ends of the protrusions and then injection molding a resin to the penetrating recesses and the penetrated portion of the through holes, or laminate molding a prepreg and pressing the same under heating and pressure, thereby forming a resin or a resin lamination molding product to the formed through holes and then cutting off the same while leaving a required amount of the resin portion to the inner circumferential portion of the through holes.
The invention (1) provides a polished work holder comprising a metal plate in which through holes are fabricated for holding a polished work, wherein the periphery of the through hole is chamfered partially or entirely and the periphery and the inner circumference thereof are coated with a resin or a resin lamination molding product.
The invention (2) provides a polished work holder comprising a metal plate in which through holes are fabricated for holding a polished work, wherein a plurality of penetrating recesses are formed to the inner surface of each of through holes, each of protrusions formed by the penetrating recesses is chamfered partially or entirely or unevenness is formed on the lateral surface at the top end of the protrusion and the periphery and the inner circumference of each of the through holes are coated with a resin or a resin lamination molding product.
The invention (3) provides a method of manufacturing a polished work holder, which comprises attaching, to a molding die, a metal plate having through holes for holding polished works in which the periphery of the through hole is chamfered partially or entirely, injection molding a resin to the through holes including the chamfered portion and then grinding to remove the resin molded to the through holes while leaving a resin portion in a required amount to the inner circumference of the through holes, thereby forming a polished work holding hole.
The invention (4) provides a method of manufacturing a polished work holder which comprises attaching, to a molding die, a metal plate having through holes for holding polished works in which a plurality of penetrating recesses are formed to the inner surface of each of the through holes, chamfering each of the protrusions formed by each of the penetrating recesses partially or entirely or forming unevenness on the lateral surface at the top end of each of the protrusion, injection molding a resin to the through hole portion including the penetrating recess, then grinding to eliminate the resin molded to the through holes while leaving the resin portion in a required amount to the inner circumference of the through holes, thereby forming the work holding hole.
The invention (5) provides a method of manufacturing a polished work holder which comprises chamfering the periphery of through holes fabricated in a metal plate for holding polished work partially or entirely, fitting a thermosetting resin prepreg of a shape conforming to the through hole into the through hole, subsequently, forming a resin lamination molding product over the entire surface of the through holes by pressing under heating and pressure, then grinding to remove the resin lamination molding product while leaving the resin lamination molding product in an amount required for the inner circumference of the through hole thereby forming a polished work holding hole.
The invention (6) provides a method of manufacturing a polished work holder which comprises forming a plurality of penetrating recesses to the inner surface of each of through holes fabricated in a metal plate for holding the polished works, chamfering each of protrusions defined by the penetrating recesses partially or entirely or forming unevenness on the lateral surface at the top end of each of the protrusions, fitting a thermosetting resin prepreg conforming to the shape of the through hole into the through hole, subsequently, forming a resin lamination molding product over the entire surface of the through hole by pressing under heating and pressure and then grinding to remove the resin lamination molding product while leaving a resin lamination molding product in an amount required for the inner circumference of the through hole, thereby forming the polished work holding hole.